The personal, social and criminal ramifications of psychostimulant abuse is an enormous problem in North America. Clarifying the neural substrates that underlie addiction to drugs of abuse is critical for designing rational pharmacological interventions with the potential to cure addicts. A point in the cycle of addiction where pharmacological intervention can be particularly beneficial is to interfere with the overwhelming desire by addicts to use drugs. The Neurobiology of Addiction Research Center (NARC) uses a rat model of cocaine-seeking and unites an assemblage of investigators with expertise in behavior, neurochemistry, electrophysiology and cell biology. An Animal Core will generate rats with a history of stable cocaine self-administration that have been withdrawn from drug in an extinction or abstinence paradigm. After withdrawal, cocaine-seeking will be induced by presentation of conditioned cues, cocaine or drug context. The rats are then dispersed to the various projects for neurobiological evaluations. This core facility will insure consistency in experimental subjects, thereby permitting more accurate associations to be made between neuroadaptations associated with cocaine-seeking. Another aspect of the NARC that will be held constant is examining the same limbic-motor circuit. Project 1 endeavors to link changes in synaptic proteins, dendritic morphology and electrophysiology in excitatory accumbens synapses that are associated with cocaine-seeking. As well, project 1 will evaluate behaviorally effective medications for effects on the cocaine associated neuroplasticity. Project 2 will explore the cellular basis underlying the capacity of prefrontal BDNF administration to ameliorate cocaine-seeking, with a focus on prefrontal output to the nucleus accumbens and ventral tegmental area. Project 3 explores the neurobiological mechanisms whereby orexin antagonists inhibit cocaine-seeking, focusing on projections to the ventral tegmental area and prefrontal cortex. Finally, Project 4 will examine novel treatments derived from the first 3 projects that possess potential for inhibiting drug-seeking behavior. Thus, this project acts as a translational program to identify systemically active compounds with the potential for entering clinical trials. In addition to this highly integrated, multi-disciplinary approach to the neurobiology and treatment of cocaine-seeking, the NARC will facilitate scientific interactions, provide oversight and mentor junior faculty, pre- and postdoctoral trainees and undergraduates. In part this will be accomplished through a Pilot Core that will directly involve young and established investigators outside the field of addiction in evaluating novel hypotheses related to the neurobiology of relapse. In summary, the NARC provides a multidisciplinary research assault on the neurobiology and medications development for cocaine-seeking and is a mechanism for actively mentoring faculty and trainees. CENTER CHARACTERISITICS